Device for stabilizing the frequency of an ultra short wave transmitter



Aprll 3, 1951 P. GUENARD 2,547,159

DEVICE FOR STABILIZING THE FREQUENCY OF AN ULTRA-SHORT WAVE TRANSMITTERFiled Aug. 27, 1946 Fig. i a /2 0 0/05 m4 mve HORN OSCILLAT f? /6 6 H9.2 v 1 057790700 CURRENT mTH INPUT RESONANT cm 0/1 V/TY I DETECTORCURRENT Q I w/r/mur INPUT 01005 I E RESO/VA/VTGAV/TY Fig. 3 RESONANT fUHF L040 5)/$AWTY 6 GENERATOR OIRGU/T H/GH TUNED AMPLIFIER DETECTOR LCURRENT a L 7 DE r50 r00 F f 8 LOW TUNED I g, DETEG TOR CUR/YEN T F- rq.7 D/FFERNT/AL 05 T50 ran CURRENT 200100014; 7/4 0 V04 T4 65 mom/rlllllll|l* 47 IN VE/Y T02. c0274, P E GUENA RD (/fic'urr Patented Apr.3, 1951 DEVICE FOR- STABILIZ ING THE FREQUENCY OF AN ULTRA SHORT WAVETRANSMITTER Pierre Guenard, Paris, France, assignor to CompagnieGenerale de Telegraphic Sans Fil, a corporation of France- ApplicationAugust 27, 1946, Serial No. 693,289

In France April 19, 1945 I Section 1, Public Law 690, August 8,1946Patent expires April 19, 1965 6 Claims. (01. 250-17) This inventionrelates to a device for stabilizing the frequency of an ultra-short wavetransmitter. ,It is more especiallyconcerned with a method" permittingof stabilizing the frequency first diode 4 is coupled to the guide 2through the intermediary of the cavity 5 of a high Q factorthrough thebranch guidesection IS; a secof a transmitter of decimetric waves with a.ond diode 6 is coupled to the guide 2 by a nontransit time generator ofanytype. It is essentunedcircuit, or' a circuit having a very low Qti-ally'chara'cterized by the guide of waves fed by factor through thebranch guide section l-B. the oscillator being coupled to tworectifiers, for The current of the diode 4 varies with the fre-'instance two diodes, one through the intermediquency of the oscillator iin response to the ary of a cavity of :a high Q factor, the otherdiresonance curve I of Fig. 2 where intensities are rectly. Thevariations of the high tensionape plotted as ordinates against thefrequencies as plied to the oscillator are controlled by thevariaabscissae. According to the purpose aimed at tions=of,. the currentof the first diode-about a by the invention, it is intended to controlthe pointsitiiated on the side of the resonance curve variations of thehigh tension a plied to the osof the cavity, this point being so chosenthat the cillator by the variations of the current of the variations ofvoltage induce variations of frediode 4 about a point 'A suitably chosenon the quency in a direction reverse to those that have side of thecurve I. The position of the point caused them. The point 01 theresonance curve A on I is fixed independently of the power de-' isfixed, on the other hand, independently of the livered by means of thediode 6, the current of power delivered, by means of the second diode,which opposes tothat of the diode 4, as it is the current of whichopposes that of the first stated more precisely hereinafter. diode. vFig. 3 shows a diagram of the principle of the My invention will be morefully understood device which permits of compensating the variafromthegfollowing specification by reference to tions of frequency of theoscillator whatever be the "accompanying drawings, in which: the origin01 these variations, by acting upon'the Figure 1 diagrammaticallyillustrates the sysvoltage applied to the pilot tube of the transtem ofmy invention; 1 mitter. To this end, a small part of the high Fig. 2- isa curve diagram comparing the op-v frequency energyis taken off the load2 of the eration of-the detector with the input resonant transmitter land sent on to the resonator 5 cavity and without the input resonantcavity; tuned to a frequency adjacent to the frequency 3 Fig. 3 showsthe system of my invention with transmitted, and to which the rectifyingdiode-.4 means for compensating the variations of fre is coupled. Therectified current varies as a funcquency oi'the'oscillator; 1 tion ofthe frequencyaccording to'the curve I ijfgliagrammatically shows onemethod of of Fig. 2.. On the I other hand, :the' resonator 5 controllingthe rectified currents in the system of being tuned in such-manner thatthe frequency myinvention; e 4 of operation F corresponds to a point Aon: the --;;Fig. 5 shows the applicationoi the rectifiers in side of thecurve I,-small variations of frequency the system of my invention to tworesonators; about that point are shown. by relatively. im

Fig. 6 is a curve diagram explaining the opportant variations of therectified current. This 7 eration fjthe circuit of Fig.5; and 40rectified current, afterbeing amplifiedin- 1,- is Fig. Tie a curvediagram showing the charac-. used-for insuring the correspondencethrough the teristic of; the difierenti-aldetector current intheintermediary-of a known device -8,- between the circuit of Fig. 5. r v 1variations of the current and the variations of flhe'followingexplanations will permit of unthe-voltage V0 applied to the pilot tubeof the derstanding, through an example of embodiment transmitter -insuch anappropriate direction that which is: by no means limitary, themanner of they compensate the very variations of frequency putting'inpractice the principle of theinvenwhich have-caused them. tion. V v c 1But, in all the foregoing exposition, it was 1111+. shows a diagram as'awhole of the device plicitly supposed that the variations of the recti-eaccording to the invention. The oscillator I feeds fied; current proceedbut from the only variat tions of the frequency of the transmitter, thatis to say that the transmitted power remains constant. lhe device ofFig. 4, conformable to the invention, permits of evading this lastcondition. For this purpose, in the grid circuit of the input valve 9 ofthe amplifier 1 there are opposed the voltages which are respectivelyproduced by the circulation through the resistances t1 and T2 of therectified currents furnished by the receivers 4 and 6, one being coupledto the resonator 5, the other to the load 2 through the intermediary ofa non-tuned circuit, it being understood that the variations as afunction of the frequency of the currents of the two rectifiers haverespectively the forms of the curvesI and II of the Fig. 2, theintersection A of which corresponds to the frequency F of operation ofthe transmitter and to a null voltage across the points M and N (Fig.4). The variations of the voltage V0 applied to the pilot tube of thetransmitter are thus controlled by the variations of the rectifiedcurrent about the point A of fixed abscissa (Fig. 2).

Fig. 5 schematically shows the invention employing two resonators. Thegenerator and feed means therefore are of the type shown in Fig. 3 andhave been indicated by the correspondingly numbered UHF generator I andthe device 8 associated with valve 9 of amplifier I through suitablecoupling circuit H. c

More generally, it is possible to couple the rectifiers 4 and 6 (Fig. 5)respectively to the two resonators i0 and H, de-tuned on either side ofthe frequencyF- to be transmitted, that is to say, having respectivelythe resonance curves I and II arranged as indicated in Fig. 6. Underthese conditions, the voltage applied to the grid of the input valve 9(Fig. 5) oi the amplifier l varies as -a function of the frequency asindicated in Fig. '7.

In addition, the device according to the invention is adaptable withoutfurther alteration to frequency modulation. To that end, it only needsto. vary, by means of the signal of a low frequency to be transmitted,the voltage appliedv to the grid of the input valve 9 of theamplifier 1. The modification of Fig. 5, for which the curvevoltage-frequency (Fig. 7) a shows a long rectilinear part about thepoint A, is particularly recommended for this application; the lowfrequency signal is applied at l2 (Fig. 5)

, While I have described myinvention in certain of its preferredembodiments I realize that modifications may be made and I desire thatit be understood that no limitations upon my invention are intendedother than may be imposed by the scopeof the appended claims.

What I claim is: l; Anultra-short wave emitter system including a,generator of ultra-high frequency, means for feeding said generator, adielectric guide excited by said generator, at least one branch guidesection on this guide including a detector, means for picking up at theoutput end of this de-' tector a current responsive to the frequency2,547,159 *iri'r:

tions on this guide each including a detector, means for opposing theoutput currents of these detectors so as to obtain a differentialcurrent responsive to the frequency variations of the generator due tothe deviations of the feed means from a predetermined condition, andmeans for injecting the said differential current in the said feed meansso, as to reduce the said deviations of the said feed means from thepredetermined conditions. v

3. An ultra-short wave emitter system includ ing a generator ofultra-high frequency, means for feeding said generator, a dielectricguide excited bysaid generator, two branch guide sections on this guideeach including a detector, one of these branch guide sections includingin addition a circuit resonant in ultra-high frequency and tuned on aslightly different frequency from the frequency produced by thegenerator for a predetermined condition of the said feed means, meansfor opposing the output currents of these detectors so as to obtain adifferential current responsive to the frequency variations of thegenerator due to the deviation in the said feed means and circuits inrelation to the said predetermined condition, and mean for injecting thesaid'differential current in the said feed means soas; to restore themto the said predetermined co'ndi' tion.

4. An ultra-short wave emitter-system includ ing a generator ofultra-high frequency, means for feeding said generator, a dielectricguide ex cited by said generator, two branch guide sec tions on thisguide each includinga detector fed through a circuit resonant toultra-high ire; quency, the said circuit being tuned in one of thesebranch guide sections above and in the other branch guide section belowthe frequency produced by the generator for a predetermined condition ofthe feed means, means for opposingthe output currents of said detectorsso as to ob-: tain a differential current responsive to the fre quencyvariations of the generator due to'the deviations in the said feedmeansand circuits in relation to the said predetermined condition, and meansfor injecting the said differential cur-:- rent in the said feed meansso as to restore them to the said predetermined condition. 4

5. An ultra shor't wave emitter systeminclud ing a generator ofultra-high frequency, means for feeding said generator, a dielectricguide ex cited by said generator, two branch guide sections on thisguide each including a detector fed through a circuit resonant inultra-high fre quency, the said circuit being tuned in once: thesebranch guide sections above and inthe other branch guide section belowthe frequency produced by the generator, a circuit for picking up adifferential voltage resulting from the o'utput currents of-the saiddetectors, means for in jecting in the said circuit a modulatingvoltage,

6. Anultra-short wave emitter system includ ing a generator ofultra-high frequency, means for feeding" said generator, a dielectricguide excited by said generator, two branch guide sec tions on thisguide each including a detecton'a thermionic tube including in itsinputcircuit twc'i resistances in series associated respectively with theoutput circuits of the said detectors so as to pick up diiferentiallythecurrents thereof, ms

5 6 grid of said tube, being thereby excited by voltage a REFERENCESCITED proportional to the resultant differential current The followingreferences are of record in the of the detectors, which isrepresentative of the me of this patent:

frequency applied at the input circuit of the said detectors, said tubehaving, in its output circuit, 5 UNITED STATES PATENTS a resistanceinserted in the said feed means, the Number Name Date feed voltage beingthereby varied, when the gen- 1,626,724 Dem'arest et a1 May 3, 1927erator frequency varies and means for adjusting 2,262,932 Guanella Nov.18, 1941 the feed voltage variation to compensate for said 2,425,981Bard et a1 Aug. 19, 1947 frequency variations. 10 2,426,193 FernslerAug. 26, 1947 PIERRE GUENARD.

